Monday, February 11, 2008

Aliens could misinterpret earth's classic songs as declarations of war if they are recklessly broadcast into space, some scientists say.

Last week NASA broadcast a Beatles song, Across the Universe, towards the North Star, in the hope it would be noticed by extra-terrestrial beings.

But scientists have urged NASA to be more cautious, saying aliens could misinterpret the song, and even take it as a battle cry.

"Before sending out even symbolic messages, we need an open discussion about the potential risks," New Scientist magazine reported Dr Douglas Vakoch of the SETI Institute as saying.

Professor Barrie Jones of Open University said: "the chances are slight, but the consequences would be huge - the end of life on Earth".

"If they have the technology to cross interstellar space to reach us, they will be so much in advance of us humans that there is nothing we could do to resist them," he said.

SETI - the Search for Extraterrestrial Intelligence - has been listening to the skies for the last 20 years.

The program uses radio telescopes to scan for any messages or noises that may indicate the existence of life on other planets.

Scientist Ainin De Horta, from the SETI Australia Centre, said the there could be dangers in broadcasting songs into deep space.

But he didn't think it would lead to an intergalactic war.

"I think the chances are pretty unlikely that it'll lead to an alien invasion, but I do think there is a point that this should be discussed by the whole world, because who knows what'll happen," Mr De Horta said.

"I think it's highly unlikely that this message will cause a reaction, and that it'll cause a reaction in our lifetime."

Radio waves travel through space at the speed of light or nearly 300,000 km per second.

The first radio transmission, sent in the 1920s, would have travelled nearly 90 light years by now.

"It's not like picking up the phone and ringing me for instance," Mr De Horta said.

"We're talking about vast distances and a response would take years from even the closet star."

SETI has had a few close calls, or what they call "candidates", but Mr De Horta says any authentic messages would have been identified.

"We get what we call candidates every so often, but none of them turn out to be something that can't be explained, like a statistical anomaly or equipment glitch."